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Carbohydrates
C, H, and O
Lipids
C, H and O (Triglyceride lipids
solid = fats while liquid = oils)
Glycosidic bonds
Ester bond between fatty acid
and glycerol
Energy storage in humans (4
cal/g)
Energy storage in humans (9
cal/g)
Is associated with water
molecules – slightly polar so it
does not contain as much energy
per mass unit
Better conductors of heat as
polar molecules in water
Glycogen is the short term
storage in humans – breaks
down quickly while starch is
used in plants
Used in anaerobic and aerobic
cellular respiration
Does not associate with water
molecules so very efficient in
having more energy per mass
unit
Poor conductors of heat so are
used as insulators under the skin
of humans
Long term energy storage in
humans – does not break down
very quickly as adipose
Can only be used in aerobic
cellular respiration
Glucose
Alpha glucose
Beta glucose
The -OH group on carbon
atom 1 points downwards
The -OH group on carbon
atom 1 points upwards
Starch
Glucose storage
in plants
Long chain of
glucose; no fixed
size
Insoluble in
water
Amylose –
unbranched &
forms a helix
Amylopectin –
branched =
globular shape
Alpha glucose
creates a curved
molecule
Cellulose
Glycogen
Long straight
chains of beta
glucose
Storage of
glucose in
animals (alpha
glucose)
Insoluble in
water
Straight chains
because of
alternating
glycosidic bonds
Creates
hydrogen bonds
(cellulose
microfibrils)
with other
chains result
strength for cell
walls
Branched chains
of glucose; no
fixed size
Branches
compact the
molecule
Stored in the
liver and
muscles
Proteins
Structure and Functions
Definition
Proteins are biochemical compounds consisting of
polypeptide sequences of amino acids that can be up
to 1000’s of amino acids long
Amino Acid sequence is determined by the genetic
code in DNA
There are 20 standard amino acids used in creating
the sequence
Amino acids are joined to one another by a covalent
bond called a PEPTIDE bond – the carboxyl group of
one aa bonds with the amino group of a second aa
Amino Acid
20 different AA’s used by ribosomes to make proteins
The R group is the deciding factor as to what the AA
is as all the amino and carboxyl ends are used in
bonding the AA’s together
There are some modifications to the AA in a
polypeptide chain – proline modifies to
hydroxyproline when in collagen – a strong
polypeptide made more stable with the change
These 20 AA’s may have been the ones around when
life on earth was formed; they are the ideal AA’s and
organisms favour them; all life is from a single
ancestor so it is difficult to use different AA’s
Anabolism example: Amino Acids combine
together through a condensation reaction to
create polypeptides
Catabolism is the breakdown of complex molecules into simpler molecules
including the hydrolysis of macromolecules into monomers ex: reverse of the above
Polypeptides
The coding to make the polypeptide comes from the
DNA in the nucleus, transferred to the ribosomes and
the proteins are constructed one AA at a time
They can be linked in any sequence so the possible
combinations are extremely high in numbers
Smallest peptide is a dipepetide. There are 20
different AA’s so there are 20 x 20 different
possibilities. Tripeptides have 20 x 20 x 20 different
possibilities and so on. Some chains are hundreds and
thousands of AA’s long – WOW!!!!
Protein Structures
Primary structure = sequence of AA’s
Secondary structure consists of two forms: i. coiled into a
helix and held there by hydrogen bonds between the Rgroups of particular AA’s and ii. Long sheets that are
pleated and again have hydrogen bonds between
particular R-groups
Tertiary structures forming globular proteins where a
three dimensional shape is created with hydrogen bonds,
disulfide bridges, London dispersion forces creating weak
interactions between both the R-groups and between the
R-groups and the water environment
Quatenary structures are three dimensional structures
that consist of many tertiary structures folded together as
one unit like hemoglobin in the RBC’s
Protein functions
For the following functions – briefly explain the role of
each
Blood clotting, Catalysis, Cell Adhesion, Cytoskeleton,
Hormones, Immunity, Membrane Transport, Muscle
Contractions, Packing of DNA, Receptors, Tensile
Strengthening, Transport of nutrients and gases,
Identify the following proteins as to their function, how it
occurs and where the proteins are created and found:
Collagen; Immunoglobin; Insulin; Rhodopsin; Rubisco; Spider
Silk